Intermediate transferer and image forming apparatus

Abstract

An intermediate transferer a toner image formed by developing a latent image on an image bearer with a toner is transferred onto includes a substrate including a polycarbonate resin and a carbon black. The intermediate transferer has a surface resistivity of from 10 to 12 Log Ω / □ when applied with a volt of 500 V, a volume resistivity of from 7.5 to 9.5 Log Ω·cm when applied with a volt of 100 V, and a difference between the surface resistivity and the volume resistivity of from 1.5 to 4.0 digits.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This patent application is based on and claims priority pursuant to 35 U.S.C. §119 to Japanese Patent Application No. 2014-051253, filed on Mar. 14, 2014, in the Japan Patent Office, the entire disclosure of which is hereby incorporated by reference herein.BACKGROUND[0002]1. Technical Field[0003]The present invention relates to an intermediate transferer equipped in image forming apparatuses such as copiers and printers, and to an image forming apparatus using the same.[0004]2. Description of the Related Art[0005]In the conventional art, a belt, especially a seamless belt, has been used for various purpose, as a member in an electrophotographic image forming apparatus. In recent years, an intermediate transfer belt system has been used in a full-color image forming apparatus, where the intermediate transfer belt system includes superimposing developed images of four colors, yellow, magenta, cyan, and black temporarily on an intermediate t...

AI Technical Summary

Benefits of technology

The present invention aims to provide a low-cost intermediate transferer that has excellent transferability and does not cause abnormal images like white spots.

Problems solved by technology

As for the aforementioned intermediate transfer belt, a system using developing units of four respective colors to one photoconductor has been used, but this system has a problem that a printing speed thereof is slow.

In this system, however, it is very difficult to accurately position images of colors to be superimposed, as the paper is affected by the fluctuations of the environment, which causing color shift in the image.

However, since an intermediate transfer belt formed of a polyimide resin has high strength and high surface hardness, it applies high pressure to a toner layer when transferring a toner image, resulting in occasional hollow images because a toner unevenly aggregates and a part of an image is not transferred.

In addition, the intermediate transfer belt has low followability with a contact member such as a photoconductor and a paper, resulting in occasional void images because of partial defective contact (gap).

Further, polyimide and polyamide imide resins are very expensive.

Particularly when a transfer material has high resistance due to low humidity environment and backside copy, a higher bias applied to form a second transfer electric filed tends to cause spot discharge in the second transfer nip, resulting in a white spot.

However, two or more coating liquids are needed, and further the polyimide resin needs heating at 400° C., which costs much.

However, this relates to releasability from a mold and the resistivity is not studied in detail although carbon black is used to make the belt conductive.

Therefore, abnormal images such as white spots may be produced.

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